Electric condenser



Mar ch 9 192s.

1,576,096 W. P. DAVEY ELECTRIC CONDENSER Filed April 22, 1924 /more:g/7al'ed with linseed oil or other compound off/1e 4 unsaturatedfatty acids.

Inventor- WheeLer p. D'cLv y HLs Attorne y ments have shown that theimpregnating" Patented Mar. 9, 1926.

UNITED STATES PATENT OFFICE.

WHEELER R DAVEY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC-TRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC CONDENSER.

Application filed April 22, 1924. Serial No. 108,248.

To all whom/it may concern."

Be it known that 1, WHEELER P. DAVEY, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Electric Condensers, ofwhich the following is a specification.

-My invention relates to electrical-condensers and particularly to thedielectric thereof. Static condensers heretofore constructed using adielectric comprising paper impregnated with a mineral oil "have beenfound to require very careful-handling especially during the process ofimpregnation in order that the finished product could be re,- lied uponto withstand its rated voltage Without breakdown. Because of theexacting. requirements incident to the materials employed, themanufacture of static condensers upon a large scale has been attendedwith many difficulties.

' An object of my invention is to provide an improved dielectric forsuch condensers which will reduce or obviate the ditficulties heretoforeencountered and in general greatly facilitates the successfulmanufacture of condensers. r

The single figure of the drawin is a diagrammatic representation of as-atic condenser involving my invention.

In accordance with my invention I employ as the dielectric or platespacing elementa non-conducting layer which, for example, may becellulose containing a compound of the unsaturated fatty acids, as forexample a glyceride represented by lin- .seed oil,

have obtained excellent results using as the dielectric several layersof a ood quality of bond paper of about onealf .mil. in thickness whichwere afterward impregnated with purified linseed oil. Experiinaterialfor ood results should be in a'comparatively high state of purificationand I have found purified oils such as mentioned Y above to exhibitcharacteristicswhich make them especially desirable for use asdielectric. materlal for condensers. For instance, the conductivity of asample of purified and dried linseed oil was found to be of the sameorder of magnitude as that of the best mineral oil, and its dielectricconstant to be about %higher than that of mineral oil,

China wood oil or castor oil, I.

erty is believed to account in a large measure for the superior resultsobtained with such substances'over those which do not spread on water.It is a fact well known to those skilled in the art that paper such asthat used in the manufacture of condensers, cables, and the like is onlywith difficulty freed from the last traces ofwater. Whensuch paperistreated with a water spreading oil,

the oil acts as though it imprisoned the residual water'in the paper sothat it is unable to affect the conductivity of the insulator as awhole.

The above-mentioned water. spreading property is not confined to theglycerides of the fatty acids as this property is possessed also by thevarious soaps of the fatty acids.

The water spreading properties of soaps of the alkali metals are alreadywell known.

Recent experiments have shown that this effect is not limited to theso-tc-alled water soluble soaps, for copper ole'ate will spread on waterto a film substantially one molecule thick.

Mention was made above of the necessity ofusing oils in a purifiedstate, the removal of water from the oil being of primary importance. Itis well known that animal and vegetable oils may be purified by chemicaltreatment and that colloidal'matter may be.

removed by filtering through such clarifying materials as fullers earth,filtering carbon, etc, and that they may be furtheE refined and dried bysuitable heat treatment.

A condenser having a dielectric involving my invention may be built upof alternate layers of conductor and dielectric in the usual mannereither by piling up the layers to form a stack or by rolling upcontinuous strips of thesame. The dielectric layers which may be .paperare preferably allowed to remain somewhat loose better to enable air andmoisture therein to be withdrawn and the pile orroll thus formed maythen be subjected to treatment in a vacuum tank. While subjected to thevacuum and preferably at an elevated temperature the impregnating oilmay be admitted to the tank and the pressure restored. The condenserelements may then be securely clamped together and immersed in apermanent receptacle containing the impregnating or other suitable oil.

Referring to the drawing, which is purely diagrammatic in character, theconducting layers 1 of one polarity are shown spaced from the conductinglayers 2 of the opposite polarity by layers of dielectric 3 which inaccordance with my invention contains or is impregnated with linseed oilor other compound of the unsaturatedfatty acids. The whole is shownimmersed in a receptacle 4 containing an insulating liquid whichpreferably is the same as that comprised in the dielectric.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is, 1. A condenser comprising a plurality of conducting layersand spacing of solid ma- 'terial therebetween containing a compound ofthe unsaturated fatty acids.

2. A condenser comprising a plurality of conducting layers and spacingof solid material therebetween containing a glyceride of the unsaturatedfatty acids;

3. A condenser comprising a plurality of conducting layers and adielectric therebetween comprising a solid non-conducting materialimpregnated with a glyceride of the unsaturated fatty acids.

4. A condenser comprising a plurality of conducting layers separatedfrom each other by layers of solid cellulose material impregnated with aglyceride of the unsaturated fatty acids. 7

5. A condenser comprising a series of conducting layers, and a series ofdielectric layers alternating with said conducting layers,- saiddielectric layers comprising sheets ;of paper impregnated with linseedoil.

6. LA condenser comprising spaced conducting elements and a soliddielectric therebetween impregnated with linseed oil.

In witness whereof,-I have hereunto set my hand this 21st day of April,1924.

'WHEELER P. DAVEY.

